Which of the following is unique to the sympathetic nervous system?

• A. Stimulation of digestive activities
• B. Release of acetylcholine at neuromuscular junctions
• C. Release of norepinephrine from postganglionic neurons
• D. Decrease in heart rate

Answer: (C)

Verified step by step guidance

1. Understand the role of the sympathetic nervous system: It is part of the autonomic nervous system responsible for the 'fight or flight' response, preparing the body for stressful situations.
2. Identify the neurotransmitters involved: The sympathetic nervous system primarily uses norepinephrine as a neurotransmitter released from postganglionic neurons.
3. Compare with the parasympathetic nervous system: The parasympathetic nervous system, which promotes 'rest and digest' activities, primarily uses acetylcholine as a neurotransmitter.
4. Analyze the options: Stimulation of digestive activities and decrease in heart rate are typically associated with the parasympathetic nervous system, not the sympathetic.
5. Conclude the unique feature: The release of norepinephrine from postganglionic neurons is a distinctive characteristic of the sympathetic nervous system, differentiating it from the parasympathetic system.